1. Field of the Invention
The invention relates to a rotary actuator in a motor vehicle suspension system.
2. Background Information
The technical journal "Auto und Verkehr" 18/1992 discloses an active stabilizer system for the reduction of the rolling motion of motor vehicles. A two-piece stabilizer system with a rotary actuator is used for this purpose, whereby a stabilizer part is non-rotationally connected to a rotary actuator housing. The rotary actuator has a number of hydraulic connections which are connected by means of hydraulic lines to a hydraulic valve in a hydraulic system. The hydraulic valve is permanently installed in the vehicle. The two components of the rotary actuator, together with respective stabilizer parts, rotate relative to one another, and also relative to the hydraulic valve. The relative motion can generally be considered to be caused by the spring-mounted wheels with which the stabilizer is engaged.
With known rotary actuator designs, a bending-torsional load is applied to the hydraulic lines which are subject to deformation as a result of the movements of the stabilizer, since the hydraulic valve does not move in conjunction with the rotary actuator. The bending-torsional load leads to rapid material fatigue which, in the worst case can result in a loss of hydraulic fluid.